Kerogen-rich shale reservoirs will play a key role during the energy transition, yet the effects of nanoconfinement on the NMR relaxation of hydrocarbons in kerogen are poorly understood. We use atomistic MD simulations to investigate the effects of nanoconfinement on the H NMR relaxation times and of heptane in kerogen. In the case of , we discover the important role of confinement in reducing by ∼3 orders of magnitude from that of bulk heptane, in agreement with measurements of heptane dissolved in kerogen from the Kimmeridge Shale, without any models or free parameters. In the case of , we discover that confinement breaks spatial isotropy and gives rise to residual dipolar coupling which reduces by ∼5 orders of magnitude from the value for bulk heptane. We use the simulated to calibrate the surface relaxivity and thence predict the pore-size distribution of the organic nanopores in kerogen, without additional experimental data.
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http://dx.doi.org/10.1021/acs.jpclett.2c03699 | DOI Listing |
J Phys Chem B
December 2024
NMR Group─Institute for Physics, Martin Luther University Halle-Wittenberg, Halle 06120, Germany.
Understanding crystallization behavior is integral to the design of pharmaceutical compounds for which the pharmacological properties depend on the crystal forms achieved. Very often, these crystals are based on hydrophobic molecules. One method for delivering crystal-forming hydrophobic drugs is by means of lipid nanoparticle carriers.
View Article and Find Full Text PDFSoft Matter
October 2024
Chemistry of Interfaces, Luleå Tekniska Universitet, Luleå SE-97187, Sweden.
The measurement of ion diffusivity inside nanoporous materials by Pulsed-Field Gradient (PFG) NMR is not an easy task due to enhanced NMR relaxation. Here, we employed multinuclear (H, P, and Li) NMR spectrometry and diffusometry to probe ion dynamics of a fluorine-free battery electrolyte comprising the [P][MEEA] ionic liquid (IL) and LiMEEA salt in a 7 : 3 molar ratio, confined in three different nanoporous SiO glasses with pore diameters of 3.7, 7 and 98 nm.
View Article and Find Full Text PDFNat Commun
October 2024
Department of Chemistry, University of Antwerp, Universiteitsplein 1, Wilrijk, Belgium.
Langmuir
October 2024
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, United States.
Although all hexose sugars share the same chemical formula, CHO, subtle differences in their stereochemical structures lead to their various biological roles. Due to their prominent role in metabolism, hexose sugars are commonly found in nanoconfined environments. The complexity of authentic nanoconfined biological environments makes it challenging to study how confinement affects their behavior.
View Article and Find Full Text PDFChem Sci
September 2024
Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science & Technology (BIST) Av. Països Catalans 16 43007 Tarragona Spain.
Chaotropic polyoxometalates (POMs) form robust host-guest complexes with γ-cyclodextrin (γ-CD), offering promising applications in catalysis, electrochemical energy storage, and nanotechnology. In this article, we provide the first computational insights on the supramolecular binding mechanisms using density-functional theory and classical molecular dynamics simulations. Focusing on the encapsulation of archetypal Keggin-type POMs (PWO , SiWO and BWO ), our findings reveal that the lowest-charged POM, namely PWO spontaneously confines within the wider rim of γ-CD, but BWO does not exhibit this behaviour.
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